One of the things we often do is put videos onto websites. Implementing video can be quite straight forward, especially if you want to use YouTube or have your own player, but increasingly clients also want to use the native players in the browser or device as well.
In order to make sure the maximum amount of people can view your video content, irrelevant of browser or device, you need to make sure you provide the correct video formats. MP4 and .FLV cover the usual, but OGG Theora and WebM are also recommended. OGG was the original HTML5
tag format of choice and WebM is the preferred format for browsers other than IE or Safari.
The main thing to remember is that if you want everyone to see your videos then play it safe and cater for every variation.